1. Field of the Invention
The subject invention is directed to surgical instrumentation, and more particularly, to hand instruments with shaped shafts for use in laparoscopic surgery performed through pneumatically sealed trocars, rather than conventional mechanically sealed trocars, and method of making such instruments.
2. Description of Related Art
Hand instruments for use in laparoscopic surgical procedures are well known in the surgical arts. They are typically constructed with an end effector provided at the distal end of an elongated shaft that is controlled by an actuation handle associated with the proximal end of the shaft. The end effector is designed to perform a certain surgical task such as, for example, cutting, grasping, ligating or retracting.
It is conventional for the shaft of a laparoscopic surgical instrument to be circular in cross-section. This is so the periphery of the instrument shaft can be effectively sealed within the tubular trocar sleeve through which it passes in order to gain access to the abdominal cavity of a patient during a laparoscopic surgical procedure. When a trocar having a pneumatic sealing system is employed, such as that which is disclosed in commonly assigned U.S. Pat. No. 8,795,223, the instrument shaft does not need to be formed in a conventional manner. That is, the instrument shaft need not have a circular-cross-section. This opens up the design envelope for laparoscopic instruments, allowing for differently shaped, non-circular shafts and manufacturing methods that are not currently used in the surgical art.